In the United States, the term “treaty” has a different, more limited legal meaning than that of international law. U.S. law distinguishes what it calls “treaties” from “executive agreements,” which are either “congress-executive agreements” or “single executive agreements.” The classes are all treaties under international law; They differ only in the domestic law of the United States. A multilateral treaty is concluded between several countries that establishes rights and obligations between each party and any other party.  Multilateral treaties can be regional or involve states from around the world.  “Mutual guarantee” contracts are international treaties, for example. B the Treaty of Locarno, which guarantees each signatory an attack by another.  The signing of a treaty implies that the signature of a treaty implies recognition, that the other party is a sovereign State and that the envisaged agreement is applicable in international law. Therefore, nations can be very cautious when it comes to qualifying an agreement as a treaty. For example, in the United States, agreements between the United States are pacts and agreements between states and the federal government or between government authorities are declarations of intent.
Prior to 1871, the U.S. government regularly entered into contracts with Native Americans, but the Indian Appropriations Act of March 3, 1871 (chap. 120, 16 Stat. 563) had accompanied a horseman (25 U.S.C. § 71) who effectively terminated the presidential convention by providing that no Indian nation or tribe could be recognized as an independent nation. Tribe or power with which the United States may enter into contracts. After 1871, the federal government pursued similar contractual relations with Indian tribes through agreements, statutes, and implementing regulations.  The differences mainly concern their method of authorisation. Contracts require the deliberation and approval of two-thirds of the senators present, but only executive agreements can be executed by the president alone.
Some contracts give the President the power to fill in the gaps through executive agreements and not through additional contracts or protocols. Finally, agreements between Congress and the executive branch require a majority of the House of Representatives and the Senate before or after the president signed the treaty. Contracts are not necessarily permanently binding on the signatory parties. Since international obligations are traditionally considered only by the agreement of States, many treaties expressly allow a State to withdraw as long as it follows certain notification procedures. . . .